package com.sz.util;

import javax.imageio.ImageIO;
import javax.imageio.stream.ImageOutputStream;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.Random;

/**
 * 验证码类，主要生成几种不同类型的验证码
 * 
 * 第一种：简单验证码，4位随机数字 
 * 
 * 第二种：英文字符加数字的验证码
 * 
 * 第三种：肆+？=21
 * 
 */
public class VerificationCodeUtil {
    
    private ByteArrayInputStream image;// 图像
    private String str;// 验证码
    private static final int WIDTH = 80;
    private static final int HEIGHT = 20;
    

    private VerificationCodeUtil() {
        BufferedImage image = new BufferedImage(WIDTH, HEIGHT, BufferedImage.TYPE_INT_RGB);
        initNumVerificationCode(image);
        int randomNum = new Random().nextInt(3);
        if (randomNum == 0) {
            initNumVerificationCode(image);
        } else if (randomNum == 1) {
            initLetterAndNumVerificationCode(image);
        } else {
            initChinesePlusNumVerificationCode(image);
        }
    }

    /**
     * 功能：获取一个验证码类的实例
     * 
     * @return
     */
    public static VerificationCodeUtil Instance() {
        return new VerificationCodeUtil();
    }

    /**
     * 功能：设置第一种验证码的属性
     */
    private void initNumVerificationCode(BufferedImage image) {

        Random random = new Random(); // 生成随机类
        Graphics g = initImage(image, random);
        String sRand = "";
        for (int i = 0; i < 4; i++) {
            String rand = String.valueOf(random.nextInt(10));
            sRand += rand;
            // 将认证码显示到图象中
            g.setColor(new Color(20 + random.nextInt(110), 20 + random.nextInt(110), 20 + random.nextInt(110)));
            // 调用函数出来的颜色相同，可能是因为种子太接近，所以只能直接生成
            g.drawString(rand, 13 * i + 6, 16);
        }
        this.setStr(sRand);/* 赋值验证码 */
        // 图象生效
        g.dispose();
        this.setImage(drawImage(image));
    }

    /**
     * 功能：设置第二种验证码属性
     */
    private void initLetterAndNumVerificationCode(BufferedImage image) {

        Random random = new Random(); // 生成随机类
        Graphics g = initImage(image, random);
        String[] letter = { "a", "b", "c", "d", "e", "f", "g", "h", "i", "j",
                "k", "l", "m", "n", "o", "p", "q", "r", "s", "t", "u", "v",
                "w", "x", "y", "z" };
        String sRand = "";
        for (int i = 0; i < 4; i++) {
            String tempRand = "";
            if (random.nextBoolean()) {
                tempRand = String.valueOf(random.nextInt(10));
            } else {
                tempRand = letter[random.nextInt(25)];
                if (random.nextBoolean()) {// 随机将该字母变成小写
                    tempRand = tempRand.toLowerCase();
                }
            }
            sRand += tempRand;
            g.setColor(new Color(20 + random.nextInt(10), 20 + random
                    .nextInt(110), 20 + random.nextInt(110)));
            g.drawString(tempRand, 13 * i + 6, 16);
        }
        this.setStr(sRand);/* 赋值验证码 */
        g.dispose(); // 图象生效
        this.setImage(drawImage(image));
    }

    /**
     * 功能：设置第三种验证码属性 即：肆+？=24
     */
    private void initChinesePlusNumVerificationCode(BufferedImage image) {
        String[] cn = { "壹", "贰", "叁", "肆", "伍", "陆", "柒", "捌", "玖", "拾" };
        Random random = new Random(); // 生成随机类
        Graphics g = initImage(image, random);
        int x = random.nextInt(10) + 1;
        int y = random.nextInt(30);
        this.setStr(String.valueOf(y));
        g.setFont(new Font("楷体", Font.PLAIN, 14));// 设定字体
        g.setColor(new Color(20 + random.nextInt(10), 20 + random.nextInt(110),
                20 + random.nextInt(110)));
        g.drawString(cn[x - 1], 1 * 1 + 6, 16);
        g.drawString("+", 22, 16);
        g.drawString("？", 35, 16);
        g.drawString("=", 48, 16);
        g.drawString(String.valueOf(x + y), 61, 16);
        g.dispose(); // 图象生效
        this.setImage(drawImage(image));

    }

    private Graphics initImage(BufferedImage image, Random random) {
        Graphics g = image.getGraphics(); // 获取图形上下文
        g.setColor(getRandColor(200, 250));// 设定背景色
        g.fillRect(0, 0, WIDTH, HEIGHT);
        g.setFont(new Font("Times New Roman", Font.PLAIN, 14));// 设定字体
        g.setColor(getRandColor(160, 200)); // 随机产生165条干扰线，使图象中的认证码不易被其它程序探测到
        for (int i = 0; i < 165; i++) {
            int x = random.nextInt(WIDTH);
            int y = random.nextInt(HEIGHT);
            int xl = random.nextInt(12);
            int yl = random.nextInt(12);
            g.drawLine(x, y, x + xl, y + yl);
        }
        return g;
    }

    private ByteArrayInputStream drawImage(BufferedImage image) {
        ByteArrayInputStream input = null;
        ByteArrayOutputStream output = new ByteArrayOutputStream();
        try {
            ImageOutputStream imageOut = ImageIO.createImageOutputStream(output);
            ImageIO.write(image, "JPEG", imageOut);
            imageOut.close();
            input = new ByteArrayInputStream(output.toByteArray());
        } catch (Exception e) {
            System.out.println("验证码图片产生出现错误：" + e.toString());
        }
        return input;
    }

    /*
     * 功能：给定范围获得随机颜色
     */
    private Color getRandColor(int fc, int bc) {
        Random random = new Random();
        if (fc > 255)
            fc = 255;
        if (bc > 255)
            bc = 255;
        int r = fc + random.nextInt(bc - fc);
        int g = fc + random.nextInt(bc - fc);
        int b = fc + random.nextInt(bc - fc);
        return new Color(r, g, b);
    }

    /**
     * 功能：获取验证码的字符串值
     * 
     * @return
     */
    public String getVerificationCodeValue() {
        return this.getStr();
    }

    /**
     * 功能：取得验证码图片
     * 
     * @return
     */
    public ByteArrayInputStream getImage() {
        return this.image;
    }

    public String getStr() {
        return str;
    }

    private void setStr(String str) {
        this.str = str;
    }

    private void setImage(ByteArrayInputStream image) {
        this.image = image;
    }
    

    public static void main(String[] arg) {
        VerificationCodeUtil vcu = VerificationCodeUtil.Instance();
        System.out.println(vcu);
        vcu.getStr();// str
        ByteArrayInputStream bais  = vcu.getImage();
        
        bais.read();
        System.out.println(bais);
        System.err.println(vcu.getVerificationCodeValue());//输出验证码的实际值
        try {
            System.out.println(bais.available());
            System.out.println(bais.read(new byte[bais.available()]));
        } catch (IOException e) {
            e.printStackTrace();
        }
        
    }
}